Perrier, Carlo

Technetium (Tc, [Kr]4 /65.vl), name and symbol after the Greek Tsxrmos (tech-nikos, artificial). Detected in Italy (1937) by Carlo Perrier and Emilio Segre in a sample of Mo which had been irradiated with deuterons at the E.O. Lawrence cyclotron in California. It was the first artificially produced element. 

Technetium Tc 1925 (Berlin, Germany) 1937 (Berkeley, California) Walter Noddack and Ida Tacke Noddack (both German) Emilio Segre (Italian-American) and Carlo Perrier (Italian) 130... 

Italian scientists Emilio Segre and Carlo Perrier Discovered when molybdenum was bombarded with the nuclei of a hydrogen isotope the first man-made element, hence its name, which means artificial in Greek. 

Technetium Tc 43 Carlo Perrier,Emilio Segre Italy Greek word "technikos" meaning "artificial"... 

Italian physicist Emilio Segre and his colleague Carlo Perrier discover technetium. 

The first synthetic element to be produced and identified was technetium, discovered by Emilio Segr, who is now Professor of Physics at the University of California, and a colleague, Carlo Perrier. 

This was the first man-made element, and for this reason we called it technetium, which means artificial. In this work Carlo Perrier, who was a mineralogist, helped me, and the problem was quite natural for a mineralogist because, at least with respect to effort, it was similar to digging an ore out of a mine. 

Technetium is an artificial element obtained by the radioactive decay of molybdenum. Element 43, named technetium in 1947, had been discovered in 1937 by Carlo Perrier and Emilio Segre in a sample obtained from the Berkely Radiation Laboratory (now Lawrence Berkeley National Laboratory) in California (Perrier and Segre 1937, 1947). By bombarding a molybdenum strip with 8-MeV deuterons in a 37-in. cyclotron, a radioactive molybdenum species (half-life, 65 h) had been obtained which decayed by yff-emission to a short-lived isotope (half-life, 6 h) with novel properties, identified as technetium-99m (Segre and Seaborg 1938). 

The discovery of technetium in 1937 by the Italian scientists Carlo Perrier and Emilio Segre was an important affirmation of the configuration of the Periodic Table. The table had predicted the existence of an element with 43 protons in its nucleus, but no such element had ever been found. (In fact, technetium does not occur naturally on Earth, as all of its known isotopes are radioactive and decay to other elements on a timescale that is relatively small when compared with the age of the earth.) Perrier and Segre were able to observe technetium from molybdenum that had been bombarded with deuterons. They named the element technetium, from the Greek word technetos, meaning artificial. Technetium is produced in relatively large quantities during nuclear fission, so there is currently an ample supply of the element from nuclear reactors and nuclear weapons production. 

In 1925, when Ida Noddack-Tacke, Walter Noddack, and Otto Berg first claimed the discovery of element 75, rhenium (see chapter 3), their work was dismissed because of the extremely minute quantity reported. Their case was solidly proven in 1928 when they were able to accumulate a gram of the metal. In 1925, they had also claimed discovery of the missing element 43 in samples of uranium-rich ores. However, this was also dismissed because of the extremely minute quantity evident from the weak X-ray emission line. In contrast to their subsequent success with rhenium, they could never isolate a quantity to support their claim for element 43. In recent years, evidence does appear to suggest that they probably were correct. Definitive proof was produced by Carlo Perrier (1886-1948) and Emilio Segre (1905-89), who bombarded molybdenum with neutrons. This was the first new element to be produced artificially. 

The discovery of element 43, technetium, is credited to Carlo Perrier and Emilio Segr6, who artificially produced it in 1937. However, scientists have found minute traces of technetium in the Earth s crust that result from the fission of uranium. Astronomers have also discovered technetium in S-type stars. 

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